6.6-stable review patch. If anyone has any objections, please let me know.
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From: Dario Binacchi dario.binacchi@amarulasolutions.com
[ Upstream commit 9ad86d377ef4a19c75a9c639964879a5b25a433b ]
The commit a22bd630cfff ("can: hi311x: do not report txerr and rxerr during bus-off") removed the reporting of rxerr and txerr even in case of correct operation (i. e. not bus-off).
The error count information added to the CAN frame after netif_rx() is a potential use after free, since there is no guarantee that the skb is in the same state. It might be freed or reused.
Fix the issue by postponing the netif_rx() call in case of txerr and rxerr reporting.
Fixes: a22bd630cfff ("can: hi311x: do not report txerr and rxerr during bus-off") Signed-off-by: Dario Binacchi dario.binacchi@amarulasolutions.com Link: https://patch.msgid.link/20241122221650.633981-5-dario.binacchi@amarulasolut... Signed-off-by: Marc Kleine-Budde mkl@pengutronix.de Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/can/spi/hi311x.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/net/can/spi/hi311x.c b/drivers/net/can/spi/hi311x.c index e1b8533a602e2..fb58e294f7b79 100644 --- a/drivers/net/can/spi/hi311x.c +++ b/drivers/net/can/spi/hi311x.c @@ -671,9 +671,9 @@ static irqreturn_t hi3110_can_ist(int irq, void *dev_id) tx_state = txerr >= rxerr ? new_state : 0; rx_state = txerr <= rxerr ? new_state : 0; can_change_state(net, cf, tx_state, rx_state); - netif_rx(skb);
if (new_state == CAN_STATE_BUS_OFF) { + netif_rx(skb); can_bus_off(net); if (priv->can.restart_ms == 0) { priv->force_quit = 1; @@ -684,6 +684,7 @@ static irqreturn_t hi3110_can_ist(int irq, void *dev_id) cf->can_id |= CAN_ERR_CNT; cf->data[6] = txerr; cf->data[7] = rxerr; + netif_rx(skb); } }